Impact of Alternate Wetting and Drying Irrigation (AWDI) on Water Saving and Yield of Transplanted Rice

A large-scale demonstrations was conducted on Alternate Wetting and Drying Irrigation (AWDI) on water saving and yield of Transplanted Rice in Mettur-Noyyal confluence sub basin areas of Tamil Nadu, India, by the Tapioca and castor Research station, Yethapur from the year 2019 to 2023. For adopting the safe AWDI, the depth of ponded water on the field is monitored using a ‘Field Water Tube’ which is made of 40-cm long plastic pipe having a diameter of 15 cm which is perforated with holes on all sides. The AWDI technology consumed ranges between 871 mm to 950 mm of irrigation water, higher water use efficiency (6.22 to 7.53 kg ha⁻¹ mm⁻¹) and number of irrigations were recorded between 22 to 30. Adopting AWDI in rice resulted in the highest yield of 7045 kg ha⁻¹ compared to the conventional method, which produced 5927 kg ha⁻¹across all experiments. The highest gross returns (Rs. 131927 ha⁻¹), net return (Rs. 77438 ha⁻¹) and BCR (2.99) were observed in adoption of AWDI. The AWDI will be an appropriate technology for water saving in rice. This technology saves up to 49 per cent of irrigation water without reducing yield, and it reduces the number of irrigations by 12 compared to farmers.